i can't save at all using the Steam version and I'm wondering if that's fixed using the GOG version.
If you're getting the "Disk Full" error message, do the following:
In your Documents folder:
- Create a folder, name it BioshockHD
- Double click into the folder
- Create a folder called Bioshock
- Double click into that folder
- Create a folder called SaveGames
Sorted the problem for me. Guessing a folder called Bioshock2 in BioshockHD will fix the other remaster as well.